<mat-card>
  <h3 class="title">可重用的动画 <span>useAnimation</span></h3>

  <button mat-raised-button (click)="isOpen = !isOpen">切换</button>
  <span>{{isOpen}}</span>
  <div [@openClose]="isOpen ? 'open' : 'closed'" class="open-close-container"></div>
</mat-card>